Cooking appliance and method of manufacturing housing of cooking appliance

Abstract

A cooking appliance includes a housing including a door, a cooking chamber provided inside the housing, and a heater provided to heat the cooking chamber, wherein the housing includes a bending portion, which is bent to have a bending angle and has a bending groove cut using a tool and formed at an inside of the bending portion a first portion, which extends from one end of the bending portion and a second portion, which extends from the other end of the bending portion.

What is claimed is: 
     
       1. A home appliance comprising:
 a housing comprising a door; and 
 a chamber provided inside the housing, 
 wherein the door includes, a front frame having a bending portion which is formed in the front frame, the bending portion having a bending angle and a bending groove inside of the bending portion, 
 wherein the bending portion includes a linear bending portion that is bent in an approximately linear shape, and a curved bending portion that is bent in a curve shape with a predetermined curvature, and 
 wherein the bending groove includes a first groove portion and a second groove portion, the first groove portion is formed to have an approximately linear shape, the second groove portion is formed to have a curve shape, wherein the second groove portion is formed to correspond to the curve shape with the predetermined curvature of the curved bending portion of the bending portion. 
 
     
     
       2. The home appliance of  claim 1 , wherein the bending groove is formed so that an initial inner angle of the bending groove is about 120° before the bending portion is bent. 
     
     
       3. The home appliance of  claim 1 , wherein the bending angle comprises a right angle or an obtuse angle. 
     
     
       4. The home appliance of  claim 1 , wherein the bending groove has a V-shape. 
     
     
       5. The home appliance of  claim 1 , wherein the bending groove has an asymmetric shape. 
     
     
       6. The home appliance of  claim 1 , wherein the bending portion is formed so that a thickness of the thinnest portion of the bending portion is between about 0.3 mm and about 0.35 mm. 
     
     
       7. The home appliance of  claim 1 , wherein the front frame comprises:
 a first portion, which extends from one end of the bending portion; and 
 a second portion, which extends from an other end of the bending portion, 
 wherein the first portion or the second portion comprises a curved surface portion. 
 
     
     
       8. A method of manufacturing a front frame of a door of a home appliance, the method comprising:
 fixing the front frame to a groove forming device; 
 forming a bending groove that extends from one surface in a bending direction of the front frame and has an initial inner angle, 
 wherein the forming of the bending groove includes cutting the front frame by rotating a cutting tool; and 
 bending the cut front frame by a bending angle along the bending groove so that the bending groove is placed at an inside of the cut front frame, 
 wherein in the forming of the bending groove, the bending groove is formed to include an approximately linear section and a curve section, the curve section formed to correspond to an exterior edge of the bended cut front frame. 
 
     
     
       9. The method of  claim 8 , wherein, in the forming of the bending groove, the bending groove is formed by a computer numerical control (CNC) processing method. 
     
     
       10. The method of  claim 8 , wherein, in the forming of the bending groove, the bending groove is formed so that a cross-section of the bending groove has a V-shape. 
     
     
       11. The method of  claim 8 , wherein, in the forming of the bending groove, the bending groove is formed so that a cross-section of the bending groove has an asymmetric shape. 
     
     
       12. The method of  claim 8 , wherein, in the forming of the bending groove, the bending groove is formed so that an initial inner angle thereof satisfies the following equation:
   (180°—the bending angle)≤an initial inner angle of the bending groove≤150°.
 
 
     
     
       13. The method of  claim 8 , wherein, in the forming of the bending groove, the bending groove is formed so that a thickness of a thinnest portion of the bending groove satisfies the following equation:
   0.25≤(a thickness of a thinnest portion of the bending groove/a thickness of the front frame)≤0.5.
 
 
     
     
       14. The method of  claim 8 , wherein, in the bending of the front frame, the bending angle comprises a right angle or an obtuse angle. 
     
     
       15. The method of  claim 8 , further comprising, before the fixing of the front frame, forming a gauge hole in the front frame. 
     
     
       16. The method of  claim 15 , wherein the fixing of the front frame comprises fixing the front frame in the groove forming device by fixing the gauge hole to a fixing protrusion formed in the groove forming device. 
     
     
       17. The method of  claim 8 , further comprising, between the forming of the bending groove and the bending of the front frame, processing the front frame in a form of the door by a press processing. 
     
     
       18. The home appliance of  claim 1 , wherein a ratio of a thickness of a thinnest portion of the bending groove to a thickness of the front frame, is greater than or equal to 0.25 and less than or equal to 0.5.